It may have been the world's biggest traffic jam. In April 2016, huge queues of oil tankers formed in key ports.

We used ship tracking data from Thomson Reuters Eikon to accurately plot the queues and show readers and energy clients the full extent of the delays.

The worst congestion is in the Middle East, as ports struggle to cope with soaring output available for export, and in Asia, where many ports have not been upgraded in time to deal with ravenous demand as consumers take advantage of cheap fuel.

The vessels shown in the maps were filled with oil worth around $7.5 billion. The combined daily cost of delay was $6.25 million, based on ship hire rates at the time. For dealers, a month-long delay can turn a profitable trade into a painful loss.

For sailors stuck a queue of anchored tankers, one of the biggest problems is simply wiling away the time. Unlike in previous eras, having a couple of beers to break the monotony is usually out of the question.